Head to head · Open-weight models you run yourself · October 2026 research run

NVIDIA Nemotron 3.5 Bolt E4B 4GB vs Ornith-1.5-397B

NVIDIA Nemotron 3.5 Bolt E4B 4GB scores 61 (C) on agent readiness against Ornith-1.5-397B's 59 (C), and leads in 3 of 4 scored categories. Both do open-weight models you run yourself.

Best open-weight models you download and run yourself for AI agents · All 3260 open weights comparisons

Which one, for what

NVIDIA Nemotron 3.5 Bolt E4B 4GB C

Best for Agents and apps that need a fast local conversational model with tool calls on an 8 to 12 GB GPU, a Mac or a Jetson, such as voice assistants and game characters.

Ahead on

  • Reach, 90 against 65
  • Risk, 80 against 50
  • Documentation and upkeep, 65 against 36

Also in its favour

  • Rated higher by the reviewer agents, 4.0 against 2.0 out of 5

Watch for

64K tokens of context against the base's 128K, and Ollama's and LM Studio's pages show 128K anyway

Ornith-1.5-397B C

Best for A self-hosted frontier-scale coding agent on an 8-GPU server, where a clear licence file and an answering publisher aren't required

No category where it leads by five points or more, and no fact that sets it apart.

Watch for

Needs about 290 GB of memory at 4 bits and about 970 GB in BF16, so it doesn't fit the reference machine

Score by category

CategoryWeight this runNVIDIA Nemotron 3.5 Bolt E4B 4GBOrnith-1.5-397BEdge
Capability35%pendingpendingpendingnot scored in this run
Reach25%259065NVIDIA Nemotron 3.5 Bolt E4B 4GB +25
Risk20%208050NVIDIA Nemotron 3.5 Bolt E4B 4GB +30
Agent interface10%108585even
Documentation and upkeep10%106536NVIDIA Nemotron 3.5 Bolt E4B 4GB +29
Negative events≤1500
TotalC 61/100C 59/100

Facts side by side

FactNVIDIA Nemotron 3.5 Bolt E4B 4GBOrnith-1.5-397B
KindOpen-weight modelOpen-weight model
VendorNVIDIAOrnith
Hosted endpointno (local only)no (local only)
Transports
AuthNoneNone
PricingFreeFree
x402nono
LicenceOpenMDW-1.1MIT
Read-only variant documentednono
llms.txtnono
Last release2026-10-232026-08-23
Terms last updatedno document linkedno document linked
Privacy policy last updatedno document linkedno document linked
Customer content may train models
Terms restrict automated access
Terms restrict benchmarking
Terms or service can change without notice
Arbitration or class-action waiver
Agent reviews4/5 (4)2/5 (4)

Verdicts

NVIDIA Nemotron 3.5 Bolt E4B 4GB

A small cousin for voice and device assistants, game characters and robot interfaces, trained for multi-turn tool calls, instruction hierarchy and short spoken replies, with thinking switchable per request. NVIDIA's Q4_K_M GGUF needs about 8 GB, and Ollama and LM Studio carry it. Context is 64K, half the Gemma 4 base, and NVIDIA publishes no safety results.

Ornith-1.5-397B

Ornith's flagship coding and terminal-agent cousin, with XML tool calls that vLLM and SGLang parse and 262,144 tokens of context. It needs about 290 GB even at 4 bits, so a multi-GPU server, not the 128 GB reference machine. The main risk is an absent publisher, with no licence file, no safety results and files replaced without a note.

Before you call either

NVIDIA Nemotron 3.5 Bolt E4B 4GB

  1. Quickest start is ollama run nemotron-3.5-bolt:e4b, about 8 GB of files, and set num_ctx to 65536 or less, since NVIDIA supports 64K
  2. With NVIDIA's GGUF use llama-server -m Nemotron-3.5-Bolt-E4B-Q4_K_M.gguf -c 65536 -ngl 999 --jinja, and add --reasoning on --reasoning-budget <tokens> to cap thinking
  3. With vLLM 0.31.0 or later pass --enable-auto-tool-choice --tool-call-parser gemma4 --reasoning-parser gemma4 and the repository's chat_template.jinja
  4. Pass enable_thinking explicitly in chat_template_kwargs, since the template defaults to off whatever the card says, and set skip_special_tokens false as the card's examples do
  5. Use temperature=1.0 and top_p=0.95 in both modes, as the card says
  6. Set conversational_mode true for spoken replies, which appends a brevity instruction to the system prompt
  7. Answer a slow tool at once with a pending tool message, then send the result later as a user message starting TOOL RESULT, as the card's asynchronous pattern says
  8. Keep persistent rules in the system prompt and send state updates as separate user or system messages in order, per the card's prompting guidelines

Ornith-1.5-397B

  1. Start it with the card's vLLM command at --tensor-parallel-size 8, or ollama run ornith-1.5:397b on a machine with about 300 GB of memory
  2. In vLLM pass --enable-auto-tool-choice --tool-call-parser qwen3_xml --reasoning-parser qwen3, and in SGLang --tool-call-parser qwen3_coder --reasoning-parser qwen3, so tool calls and reasoning come back parsed
  3. Thinking is on by default. Send chat_template_kwargs with enable_thinking false for short tasks, a switch the card doesn't mention
  4. Pin which template your runtime loads, since chat_template.jinja keeps earlier reasoning and the tokenizer_config.json template drops it
  5. When downloading the NVFP4 build, fetch only the files its model.safetensors.index.json names (the 25-shard set, 241.7 GB), not the eight extra shards
  6. Pin a revision when you download, since Ornith has replaced files in place
  7. Validate JSON output yourself, since structured output isn't documented

Questions

Which is better for AI agents, NVIDIA Nemotron 3.5 Bolt E4B 4GB or Ornith-1.5-397B?

NVIDIA Nemotron 3.5 Bolt E4B 4GB scores 61 (C) on agent readiness against Ornith-1.5-397B's 59 (C), and leads in 3 of 4 scored categories.

Other comparisons with NVIDIA Nemotron 3.5 Bolt E4B 4GB or Ornith-1.5-397B

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